The overall objectives of this research program are to assess the development of audiovisual speech perception in hearing-impaired infants who receive cochlear implants and to identify potential preimplantation behavioral predictors of later speech and language skills. Two behavioral testing procedures are currently being used in the Infant Language Laboratory at the Indiana University School of Medicine to study speech perception and language development in normal-hearing and hearing-impaired infants: Visual Preference and the Preferential Looking Paradigm. In these procedures, infants are seated in a sound booth in front of a TV monitor from which auditory and visual stimuli are presented. The duration of infants' looking times to different auditory-visual displays is measured. In Project I, we propose to use Visual Preference and the Preferential Looking Paradigm to investigate the development of multimodal speech perception skills and visual attention and lip reading skills in hearing-impaired infants before and after cochlear implantation. Eye movement measures that have been successfully developed in research with normal-hearing infants will also be used to obtain more precise measures of infants' gaze fixation and latency times of these fixations. In Project II, we propose to use eye movements to explore hearing-impaired infants' visual attention and lip reading skills prior to and following cochlear implantation. The proposed research addresses pressing clinical issues regarding the potential benefits of early cochlear implantation on hearing-impaired infants' multimodal speech perception and language development. Measures of audiovisual speech perception will provide clinicians and researchers with important behavioral markers for tracking hearing-impaired infants' progress and benefit in developing speech and language skills following cochlear implantation.